Model output discussions pm 31/12/15

[Zakos]

15 minutes ago, Steve Murr said:

You may want possibly reconsider the words from

best so far to not quite as sh*te -

whilst the anomalies may show a partial -AO they also represent a classic +NAO with negative anomalies over iceland & positive anomalies extending east into europe away from the azores -

so classically mild for the UK- also the negative AO forecasts have somewhat tailed off to the mean now only showing around -2 & the clear drivers of this pattern are the + PNA ridge & the Kara high...

no good for us im afraid....

aha yes very true, and realistically it couldn't really get much worse than the original forecast. 

I know the chart itself is not very promising.

 I should have made it clearer, but I was mainly referring to the rapid switch in the forecast, which could potentially be pointing towards a favorable pattern change mid month onwards. 

It is at least a step in the right direction, I would have thought we would have more chance of some transient cold with the latest forecast. 

[nick sussex]

If we're not going to get any northern blocking then its going to be difficult to sustain any colder conditions unless a ridge can topple towards Scandi. What would help in the earlier timeframe is for that upstream low to deepen which would provide some better WAA.

 

[Cheese Rice]

 

Perhaps some frontal snowfall Thursday morning.

 

[cyclonic happiness]

14 minutes ago, nick sussex said:

If we're not going to get any northern blocking then its going to be difficult to sustain any colder conditions unless a ridge can topple towards Scandi. What would help in the earlier timeframe is for that upstream low to deepen which would provide some better WAA.

 

Even a toppler would be welcome to most folk, it's absolutely horrendous that we can't even get a frost, let alone snow.

At least the models are showing a bit of snow in FI, that was missing a couple of months ago.

[knocker]

The GEFS anomalies this evening have some interest. Upstream At T240 they have trough eastern Pacific, strong ridging Alaska, trough southern US and ridging into Greenland. Downstream LP NW of the Uk with associated trough. Not good news because we get the jet winging out of the southern states straight across the pond delivering some wet and windy conditions to the UK. Nothing new there then.

But the latest missive from the woodshed indicates some interesting facets in the ext period. Upstream the Alaska ridge is less intense and there is a trough in the western Atlantic, Downstream the trough has been replaced with ridging to the west of the UK and there is a more distinct trough to the east. This upper air structure has various possibilities vis the surface analysis including HP setting up just to west with the UK in a settled NW flow or even sharper ridging and the trough a little further west which would open up the possibility of cold northerlies and copious amounts of snow. The latter would be the outsider with Ladbrooks.

The alternative of course is that ecm will differ.

Edited January 3, 2016 by knocker

[Cloud 10]

The 12z ECM seems to want to start the party early.

 

Is this a case of the models under-estimating heights over the pole?

 

[Paul_1978]

31 minutes ago, cyclonic happiness said:

Even a toppler would be welcome to most folk, it's absolutely horrendous that we can't even get a frost, let alone snow.

At least the models are showing a bit of snow in FI, that was missing a couple of months ago.

I can't really remember any examples of long lasting northerlies (eg 5-7 days plus) that were snow laden. 

Of the top of my head, most big snow events for England and Wales have been as a result of easterlies and fronts bumping in from the south or west. Sometimes fronts from the east itself. 

I'd like to see a northerly that properly delivers snow and isn't just a "toppler". 

Details of any past examples would be good. 

[nick sussex]

A few things to note from the ECM, the trend seems to be to edge the jet further south.  Upstream we really need to see that low in the eastern USA deepen at T192hrs.

[SMU]

As bad as the GFS is - The ECM is at the other end of the scale with significantly better cross polar heights precluding a more significant negative AO

again - as I think I mentioned yesterday - a Stella run for Scotland - with lots of snow-!

some snow for the low Thursday as well

 

s

[Mucka]

Just now, nick sussex said:

A few things to note from the ECM, the trend seems to be to edge the jet further south.  Upstream we really need to see that low in the eastern USA deepen at T192hrs.

Yes at least ECM offering a better chance for some transient snow further North here and there.

Re positive height anomalies over Greenland. It is nice to have those height rises aided by residual Scandi trough and Arctic ridge/high but with out an anomaly for showing an Atlantic ridge then they will be deceptive as it is very difficult to get any cold to the UK without blocking off the Atlantic and that anomaly will naturally pull West. In other words we need an Atlantic ridge regardless of positive height anomalies over Greenland.

 

This looks a little more promising than GFS.

 

[Zakos]

GFS

ECM

ECM shows the Cold air pushed further west on Wednesday.... Possibly some frontal snowfall in northern and eastern areas before the Atlantic pushes through? 

Edited January 3, 2016 by Zakos

[Cloud 10]

 

[Catacol]

15 minutes ago, knocker said:

But the latest missive from the woodshed indicates some interesting facets in the ext period. Upstream the Alaska ridge is less intense and there is a trough in the western Atlantic, Downstream the trough has been replaced with ridging to the west of the UK and there is a more distinct trough to the east. This upper air structure has various possibilities vis the surface analysis including HP setting up just to west with the UK in a settled NW flow or even sharper ridging and the trough a little further west which would open up the possibility of cold northerlies and copious amounts of snow. The latter would be the outsider with Ladbrooks.

 

Hehe - here we go! If ever we needed evidence here it is. GP has stuck to his guns, Tamara nips in with a second torpedo... and now Knocker is running for the woodshed as "cold northerlies and copious amounts of snow" are inbound. Ladbrookes bound to be the loser here, because teleconnections are strongly pointing to a proper change.

Keep the faith....

Yet another model pointing to height rises to our west as a precursor to a northerly incursion followed by......

 

[tight isobar]

Should see a somewhat more direct northerly. .

Digging deeper south!!

@ecm last frames

[bluearmy]

ecm 12z over the pole at day 8 - if only

be interesting to see if the parallel is similar later on.

like i said earlier, days 8/10 may well hold interest to our west. perhaps the profile to our north aswell

[nick sussex]

Yessssssssssssssssssssssssssssss!

At last winter arrives to the UK, the MJO change you can believe in!

[January Snowstorm]

Storming ecm run

In line with gp's thoughts also. Winter here we come!!

[northwestsnow]

2 minutes ago, nick sussex said:

Yessssssssssssssssssssssssssssss!

At last winter arrives to the UK, the MJO change you can believe in!

You naughty ramper sussex!!!! Great ecm, come to papa

[Mucka]

Close to perfection from ECM Atlantic ridge meets Arctic high?

Edited January 3, 2016 by Mucka

[Allseasons-Si]

Hehe!

big

216 hrs

240 hrs

Edited January 3, 2016 by Allseasons-si

[radiohead]

A nice chart, but let's not forget that this is 216 hours away. We've seen great charts at this timeframe several times this winter that never came to pass. No champagne yet....

Edited January 3, 2016 by radiohead

[nick sussex]

Just now, northwestsnow said:

You naughty ramper sussex!!!! Great ecm, come to papa

Well given the garbage synoptics of December I lost myself then! lol

Ignore the twitterati and the MJO derision from some quarters. Those synoptics would have zero chance of appearing without the MJO.

[Daniel*]

OMG - Huge sudden developments. 

UTTERLY FANTASTIC!!!

[Cloud 10]

ECM at 240hrs..........Chooooo...Chooooo.

 

[I remember Atlantic 252]

I posted 252 GFS chart earlier, showing possible change, ECM 240 also hinting at something drier, FI now, details will change, but change of some kind hopefully